One of the most reliably blissful seconds of national TV happens every weeknight between 12:35 and 12:36 a.m. That is the brief second during the drums-and-trumpet fanfare of the credits of “Late Night With Conan O’Brien” when the camera settles on Richter. Richter, who usually curtsies, or makes a face, or laughs or does a little dance, broadcasts a huge and hilarious presence just by being. His job does not seem to hold him, does not seem quite right. Which is obviously why Richter has announced he’s quitting “Late Night” at the end of this television season, and why the show has shrewdly announced that there are no plans to seek his replacement — implying that he cannot be replaced.

He can’t. For Andy Richter is perhaps the first sidekick in talk show history whom it is a pure pleasure to watch. Maybe because he’s somehow managed to surpass the pathos that is sidekickery. I am thinking specifically of the Hank Kingsley character from “The Larry Sanders Show.” Played by Jeffrey Tambor, Hank, host Larry’s sidekick on a fictionalized TV talk show, was pathetic, egomaniacal, deluded, mean and heartbreaking nonetheless. Forced to play — and be — second fiddle to another pathetic, deluded, heartbreaking egomaniac, Hank was forever the butt of the joke — investing in a failing restaurant, holing up with hookers and making unsuccessful bids to strike out on his own by courting commercial endorsements for defective products such as exercise equipment that caused back injuries. He wasn’t a laugh, he was a laughingstock.

Conan and Andy have settled in. Remember the first couple of seasons of the show, when Conan was so nervous and so green that watching this show before bed would keep you up at night, just from the sheer jitters of watching this guy you feel for flounder and flub? Because you were rooting for him like he was some little kid at a piano recital who was on the verge of tears for messing up his Mozart. No longer. There is something very real and relatively relaxed about Conan now.

The other night, Conan and Andy were in the middle of their recurring bit “If They Mated,” in which the theoretical progeny of romantically linked celebrities is pictured through garish photographic montages. Conan, for some reason, reached into the air to touch the title graphics, telling Andy, “Someday, I’m going to catch me a logo.” “Oh! You’ll do it!” Andy replies. The words are classic sidekick dialogue — beefing up the host. But Richter’s genius is that he plays into it, plays with it, deconstructs the sidekick role. Just as O’Brien is wearing a classic Johnny Carson suit and is backed by a Johnny Carson big band while conveying a subversive sensibility that is informed by rock ‘n’ roll, Andy Richter looks like an Ed McMahon sidekick without actually being one.

If I were Andy Richter, Ed McMahon’s autobiography of last year, “For Laughing Out Loud,” would have scared me silly. (If you are on an airplane and you would like to pique your row’s interest, just bring along a copy of the McMahon book — and underline.) McMahon is the Foucault of sidekick theory, and if this isn’t one of the best memoirs I’ve ever read, it’s one of the saddest. Starting with its first sentence: “I will never forget the very first time I met a young man named Johnny Carson.” The first sentence! Of his autobiography! If ever there were a sentence that should be about him and not the man who eclipsed him for 30 years, it is the beginning of his own autobiography. McMahon, who hosted his own television and radio shows for years before becoming Carson’s foil, writes, “I understood that my job was to support Johnny Carson. I didn’t tell the jokes, I set up the jokes. I didn’t get the laughs, I helped him get the laughs … At times I had to consciously stop myself from responding to something he said; I’d always had my own shows, I’d always been free to say whatever popped into my mind. But after a few weeks I had slipped quite comfortably into the role of straight man, his second banana.”

It is understandable why Andy Richter is quitting “Late Night”: Not because of the first half of the show, in which he is a vital participant, but because of the second half, when he has to sit in a chair on the set, McMahon-like, and not say a word. It’s a waste. Though he’s rarely on-screen as O’Brien does the interviews, I often entertain myself through the endless succession of interviewees with nothing to say wondering, What’s Andy thinking? Why isn’t Conan just talking to Andy? Andy’s more interesting than this (fill in name of supermodel, athlete, movie star here).

These what-about-Andy questions point to a fundamental fact of the sidekick job: It is not modern. The host-sidekick relationship is practically feudal. It is hierarchical and therefore flawed. The modern paradigms are loner hero or group effort — individuals or the masses. The sidekick is an outcast. Neither part of a group nor out on his own, not audience nor star, the sidekick lives in a lonely no man’s land, his chair so near and yet so far from the action. I’m surprised it took Andy Richter, who is both everyman and a singular star, so long to leave.

When a candidate’s shortcomings — or even his alleged shortcomings — become part of the late-night yuk-yuk fest, there’s trouble. Until now, Texas Gov. George W. Bush had been spared this bizarre American hazing ritual. Not any more.

“They’ve got a problem on their hands,” says a senior GOP official.

For months, Bush supporters, from congressmen to Iowa voters, have given the same, somewhat Machiavellian answer when asked why they were backing the Texas governor: because he could win. Of course, there’s no shame in wanting to back a winner — indeed, it was one of the chief reasons why Democrats supported then-Gov. Bill Clinton back in ’92. And it’s one of the most cogent arguments against the presidential candidacy of former veep Dan Quayle. It’s not that there’s anything wrong with him, Republicans will tell you, it’s just that Quayle is such damaged goods he doesn’t stand much of a chance of winning.

But if you live by electability, you die by electability. And as Bush joins Dan “a mind is a terrible thing to lose” Quayle as a resident in the Hall of Punchlines, suddenly his electability doesn’t seem so guaranteed.

That the drug issue could become a problem for Bush has been known for a long time. Even many of the popular Texas governor’s most ardent official supporters believed that sooner or later he’d have to address the rumors about his self-described “irresponsible” youth. But the way Bush addressed those rumors in the last few days has only added fuel to the fire.

Under a barrage of tenacious media inquiries, as well as polling data indicating that the American people find the question relevant, Bush finally decided to abandon his refuse-to-answer-questions strategy. In a testy exchange with a reporter on August 18, he said that he would be able to pass the traditional White House background check question as to whether he’d used drugs in the past seven years.

But that answer only raised more questions than it answered, and amid a hail of media criticism Bush felt impelled to issue yet another clarification the next day, extending the time frame when he could have passed the background check to include the time when his father was president — “a 15-year period.” Finally, a Bush spokesperson expanded the definition yet again, stating that Bush was saying he had not used illegal drugs at any time since he was 28, in 1974 — the year he graduated from Harvard Business School and moved back to Texas.

(The Clinton White House background check, it should be noted, asks prospective senior officials if they have ever used illegal drugs since the age of 18. Bush refuses to answer that question.)

“There are two issues operating here,” says a Democratic strategist. “What went up his nose then, and what comes out of his mouth now. And on the latter, he’s backtracking already.” This strategist said the last few weeks of media coverage — which included a Talk Magazine interview in which Bush repeatedly used the word “fuck” and made light of the execution of Carla Fay Tucker — made him “wonder if this guy is clear at how high a level he’s playing.”

But it’s not just Democratic strategists, liberal reporters, late-night talk show hosts or even Bush’s Republican opponents who find this issue relevant. “Bush has now created this whole narrative which could be interpreted as Clintonian obfuscation,” says William Kristol, editor of the conservative Weekly Standard. “And that chips away at this picture we’ve been presented with of Bush as the white knight leading Republicans back into the White House.”

Bush tried to frame the issue as involving the “politics of personal destruction,” saying “the people of America are sick and tired of this kind of politics. And I’m not participating.” But all evidence points to the fact that the American people do, in fact, find it relevant whether or not a presidential candidate has ever used illegal drugs. In February, a Gallup poll indicated that 53 percent of the American people surveyed would want to know if a candidate had “used drugs in the past.” Last week, a Fox News/Opinion Dynamics poll showed that 69 percent of those asked wanted to know if a candidate had used cocaine.

The conservative media seems to agree. “Whether, and under what circumstances, a candidate has used cocaine is more relevant to his fitness to serve than whether he has had premarital or adulterous sex, two questions Bush has answered,” opined the National Review this past week. In an August 20 editorial titled “Come clean, Mr. Bush,” the Washington Times piled on with characteristic relish. “Our distaste for these sorts of questions does not obviate the fact that Mr. Bush, who wants to be the chief law-enforcement officer of the land, has not denied using cocaine, period … Should the actions of Mr. Bush in the dim past be a concern to prospective supporters? Well, yes — on several levels. First, and most obviously, is the issue of candor. We’ve had almost eight years now of shifty double-talk from the president; the country deserves a leader who can speak without his hearers needing decryption equipment to parse his meaning … More serious, however, is the issue of hypocrisy. If Mr. Bush once sampled cocaine recreationally — an activity that can result in a felony conviction and jail time — how is it that he can advocate harsh sentences for nonviolent drug offenders?”

Behind closed doors, Republican officials, money-men, state party chairmen and other muckety-mucks are tugging at their collars, pacing, and wondering aloud if they bet on the wrong horse.

“A lot of people have invested an awful lot in George W.,” says Kristol. “If his campaign were to crash, it could be an even more spectacular crash than we’ve ever seen before, because it has been so propped up.”

The whims of the Republican electorate are even tougher to gauge. Says the Washington representative of a major conservative grass-roots organization, “The religious right’s belief is that they don’t believe [Bush] was a quote-unquote Christian until after all this (the alleged use of illegal narcotics) was over. So if they remain true to their beliefs, and forgiveness, and Christian nature, I don’t think this should have an impact.

“But in general people aren’t as compassionate as they say they are,” the conservative activist goes on. “They might think, ‘Well, I got through the baby boom without using drugs,’ and ‘What kind of message will this send to kids?’ And I can’t say that a lot of our social conservatives were ever excited about George W. But they said that he was electable, and ‘We gotta win.’ I’m really intrigued to see what angle they take on it.”

The longer Bush drags this process out, the worse he’s going to look. Sooner or later, Bush is going to have to realize that he’s not running for president of his fraternity. If he can’t deal with media inquiries about whether or not he’s used recreational drugs, then one wonders how he’ll be able to deal with crises of a taller and more substantial order. This process is — and rightly so — the most arduous and painstaking job interview in the world.

“The whole thing just makes me wonder,” says Kristol. “He could have just said that he experimented with drugs when he was young, he deeply regrets it, kids shouldn’t do it today, and good-bye.” The fact that he didn’t is “a little weird,” Kristol says. “It’s a little unnerving.”

The Democratic strategist says that Kristol might not be the only one unnerved by Bush’s faltering. “It affects Bush’s electability in that it makes people realize that they were never really sure as to why people thought this guy was electable to begin with,” the strategist says. “There’s nothing there in terms of his accomplishments, nothing as far as his general profile, nothing in terms of his leadership with the Republican Governors Association — he’s just a good-looking, articulate guy who seems to be relatively moderate … It’s image that’s done it so far for him, and I’ve been impressed with how he’s done it so far. But image — you live by it and you die by it.”